Bacillus thuringiensis
![](/Images/godic/202501/09/Bt-toxin-crystals3742.jpg")
![Gram stain of Bacillus thuringiensis under 1000 X magnification](/Images/godic/202501/09/Bacillus_thuringiensis3742.jpg")
![Bt toxins present in peanut leaves (bottom image) protect it from extensive damage caused by Lesser Cornstalk Borer larvae (top image).[41]](/Images/godic/202501/09/Bt_plants3742.png")
![Kenyans examining insect-resistant transgenic Bt corn](/Images/godic/202501/09/Btcornafrica3742.jpg")
Bacillus thuringiensis (or Bt) is a Gram-positive, soil-dwelling bacterium, commonly used as a biological pesticide. B. thuringiensis also occurs naturally in the gut of caterpillars of various types of moths and butterflies, as well on leaf surfaces, aquatic environments, animal feces, insect-rich environments, and flour mills and grain-storage facilities.